This invention relates generally to rear projection television receivers and particularly to the relatively large mirrors used in such projection receivers.
Rear projection type television receivers are very popular due to the large display screens that are available for the enjoyment of the user without necessitating special installations and/or large viewing areas. In such receivers, three color cathode ray tubes (red, green and blue) project an image onto a mirror, with the image being reflected (and magnified) onto a display screen. The large mirrors, which can be on the order of 40xc3x9730 inches, are not only expensive, but heavy.
Recently, some rear projection television receiver mirrors have been fabricated of a metallized plastic film that is tightly stretched and secured to a relatively light-weight aluminum frame. For example, as discussed in U.S. Pat. No. 5,896,236, a trapezoidal shape, U-shaped frame is secured to a cabinet (at an appropriate angle) by brackets at its corners, or by welding. A rigid backing, in the form of about a one-half inch thick sheet of styrofoam is secured in the frame very close to the metallized plastic film. The metallized plastic film is stretched, wrapped around the frame and secured to both the backing and to the back of the frame by an adhesive. The excess metallized plastic film is trimmed and the assembly is subjected to heat for a short time to cause the stretched metallized plastic film to shrink somewhat. Suitable mounting brackets are affixed to the frame. A major drawback of such a mirror is that it is relatively expensive to manufacture because it is labor intensive, since the adhesive is manually applied and the metallized plastic film is hand-wrapped about the frame. Moreover, the resultant mirror often exhibits deformations due to wrinkling of the metallized plastic film unless the hand-wrapping is carefully done.
Accordingly, it would be desirable to provide a mirror for a rear projection television receiver that is lightweight and simple to manufacture.
In accordance with the present invention, a composite laminate mirror is provided. The mirror includes a rigid substrate and a reflective sheet laminated to the rigid substrate.
In accordance with one aspect of the invention, the rigid substrate is a glass substrate.
In accordance with another aspect of the invention, the reflective sheet is a flexible plastic sheet. The reflective sheet may have a multilayer construction that includes a metallic film such as Mylar(trademark), for example.
In accordance with another aspect of the invention, the reflective sheet includes a second substrate and at least one thin film layer deposited on the substrate. The second substrate may be a metallic sheet such as a rolled metal sheet. Alternatively, the second substrate may be a plastic sheet.
In accordance with yet another aspect of the invention, the thin film layer includes a silver layer.
In accordance with another aspect of the invention, a thin film silicon dioxide layer is deposited on the substrate. Additionally, a passivating layer such as silicon nitride may be deposited on the silicon dioxide layer. A thin film silver layer may be deposited over the passivating layer.
The present invention also provides a video projection device that includes a cabinet having front and rear sections and a projection tube for projecting a video image. The video projection device also includes a screen located in the front section of the cabinet. The screen has a first surface onto which the video image is projected and a second surface for displaying the video image so that it is observable by a viewer. A mirror is arranged in the cabinet for reflecting light to the first surface of the screen. The mirror is a composite laminate mirror that includes a rigid substrate and a reflective sheet laminated to the rigid substrate.